CEM liberty, Руководство пользователя

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Reagents and Concentrations
Reagent Quality
The quality of reagents used for synthesis, including the age of reagents, will have a significant impact on the quality of
peptides produced. Solvents should be higher than ACS grade. DMF should not be used if it is more than six months old.
TFA that has discolored (is no longer clear) should not be used; this can result in incomplete side chain deprotection.
Solid/undissolved amino acids should be stored at room temperature for no longer than six months, or in a freezer for no
longer than a year.
Reagents and Stability
Reagent Reagent Stability
Amino Acids in solution Two weeks*
Activators: DIC One month
Activator and Activator Bases: HBTU, 6-Cl HBTU, HATU, HOBt, 6-Cl HOBt, HOAt and Oxyma Pure, DIEA in NMP Two weeks
Deprotection solution One month
Cleavage Cocktail 1 day
* Notably, His is only stable for one week. Val, Ile, and Leu will begin to precipitate sooner than other amino acids. The reagent dip tube
filter(s) will need to be replaced if amino acids begin to crystallize.
The Liberty Blue uses stock solutions of all reagents. The table below details the concentrations used on the Liberty Blue
and/or CEM’s preferred reagents.
Reagents 0.005 mmol 0.01 mmol 0.025 mmol 0.05 mmol 0.1 - 0.5 mmol 1.0 - 5.0 mmol
Wash Solvent*
DMF DMF DMF DMF DMF DMF
Deprotection
Cocktail 4% Piperidine
in DMF
or
2% Piperazine
(w/v) in
EtOH:NMP
(10:90) 4% Piperidine in
DMF
or
2% Piperazine
(w/v) in
EtOH:NMP
(10:90) 20% Piperidine in
DMF
or
10% Piperazine
(w/v) in
EtOH:NMP
(10:90) 20% Piperidine
in DMF
or
10% Piperazine
(w/v) in
EtOH:NMP
(10:90) 20% Piperidine
in DMF
or
10% Piperazine
(w/v) in
EtOH:NMP
(10:90) 20% Piperidine
in DMF
or
10% Piperazine
(w/v) in
EtOH:NMP
(10:90)
Amino Acids 0.04 M in DMF 0.08 M in DMF 0.2 M in DMF 0.2 M in DMF 0.2 M in DMF 0.4 M in DMF
Activator**
0.05 M DIC in DMF 0.10 M DIC in
DMF
0.25 M DIC in DMF 0.50 M DIC in
DMF 1.0 M DIC in
DMF 1.0 M DIC in
DMF
Base 0.05 M Oxyma in
DMF 0.1 M Oxyma in DMF 0.25 M Oxyma in
DMF
0.5 M Oxyma in DMF 1.0 M Oxyma in DMF 1.0 M Oxyma
in DMF
*NMP is suitable as a wash solvent or for dissolution/dilution of reagents, but requires 75°C coupling cycles to reduce the risk of insertions.
**View the CarboMAX
™
application note, ap0124, at www.cem.com for further details.
Alternative Reagents
Piperidine/Piperazine
Piperazine is recommended as an alternative to piperidine. Piperazine has limited solubility in DMF and NMP but shows
improved solubility and deprotection activity in a solution of 10% ethanol in NMP by volume.
HOBt/HOBt • H
2
O/Oxyma
Anhydrous HOBt is considered explosive. The HOBt monohydrate can be used as a direct substitute for anhydrous HOBt
and is stable to ship. Oxyma can also be used as a direct substitute for HOBt.